Drowning chamber

A Drowning chamber is a design allowing to automate the slaughter of critters, and save duplicants some labor and health.

Auto-wrangling
A small room with a Critter Drop-Off and optional Duplicant and Critter sensors, where excess of critters get deposited and drowned on preset condition be it number of critters, fullness of refrigerators, time of day, or carelessness of duplicants.

Liquids can be either pre-pumped and dropped in (somewhat energy-intense and slow) or raised from below through Mesh Tiles with timed Mechanized Airlocks (fast and low-energy, but requires more automation). The escape route for gases shall not be forgotten or they might get compressed, saving some lives.

Eggs from the stables can be shipped to a natural hatchery next to the drowning chamber. If the stables need replenishment the chamber can be locked and a rancher can auto-wrangle an adult critter. Since the critters in the stables don't suffer from overcrowding they produce an enormous amount of eggs and thus meat.

Thoroughness of drowning varies by species. Hatches will drown in liquid one tile deep, while wall-walkers and floaters will require complete flooding of the chamber.

Adjacent type
To avoid wrangling errands, drowning chambers can be built directly adjacent to the stable regularly suffering from the overpopulation. There is no way to force critters inside, but with an open airlock they will wander inside from time to time anyway, at which point the chamber can be locked and activated by critter sensor.

Egg drowning
Critter eggs can incubate underwater, which allows to "pre-drown" them into the static water pit, and increase the caloric output.

This setup can be automated with Shipping system on both input and output, and will not require duplicant labor at all. However, it is markedly slower, since eggs have to incubate naturally.

Trivia

 * Sometimes referred to as evolution chambers in the community.